Coating: 24k gold over (we can made a special type of coating for your personal preference). Materiel : 925k sterling silver some of my items vermeil gold over silver for looks rich. But i can finish in silver too. If you send us a photo of your desired model you can send your gem. We can do it for you.We can make any design you want with natural gem. You just want it , we do. You can find other signet necklace models from the link below. This item is made of bronze and silver, labradorite.